Fuel equalization system

ABSTRACT

A fuel equalization system includes a filter box for accepting an air stream and a fuel stream, the air stream and the fuel stream mixing to form a mixed air/fuel stream. A blower is provided that has an inlet for accepting the mixed air/fuel stream from the filter box. An air deflection member is positioned in the path of the mixed air/fuel stream, between the filter box and the inlet, so as to reduce the turbulence of the mixed air/fuel stream.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 60/680,805, filed on May 13, 2005, and herein incorporated byreference in its entirety.

FIELD OF INVENTION

The present invention relates, in general, to a fuel equalizationsystem, and deals more particularly with a fuel equalization system thatis capable of maintaining proper air/fuel mixtures even during times ofdecreased or blocked air flow.

BACKGROUND OF THE INVENTION

Burners are utilized in many integrated systems, such as in boilers,furnaces and water heater applications. These burners are typically fedan enriched air stream containing a predetermined concentration of fuelmixed therein. Of great importance, therefore, is the ability of thesystem to maintain a proper air/fuel mixture during operation of thesystem.

Typically, a filter box includes one or more orifices to accept incomingair and fuel streams. A blower is operatively connected to the filterbox, and propels the air/fuel mixture from the filter box, to anintegrated burner. Any blockage of the incoming air or fuel streams, orof the flue leading to the burner, will cause a change in the air/fuelmixture being fed to the burner, with a corresponding potential for theharmful buildup of CO.

Known systems oftentimes employ one or more sensors within the filterbox coupled with a variable speed blower to regulate the introduction ofthe air/fuel mixture to the burner. While these systems operatereasonably well during normal times, they suffer under blocked-flue orblocked-air inlet conditions due to the swirling air currents created bythese adverse conditions. That is, known systems arrange the air/fuelinlet orifice(s) adjacent to, or near, the blower inlet, therefore theturbulence created at the air inlet by a blockage creates an ‘implied’flow in and around the sensors. Thus, during times of blockages, thesensors of known systems are incapable of accurately controlling thedesired air/fuel mixture, due to the swirling and turbulent impliedflows washing over the sensors.

Known systems are therefore unable to accurately control the air/fuelmixture during times when the air inlet, or flue, is partially orcompletely blocked.

With the forgoing problems and concerns in mind, it is the generalobject of the present invention to provide a fuel equalization systemthat can accurately detect and respond to situations of air blockage soas to maintain safe air/fuel mixtures.

SUMMARY OF THE INVENTION

It is one object of the present invention is to provide a fuelequalization system.

It is another object of the present invention is to provide a fuelequalization system which is capable of maintaining a desired air/fuelratio

It is another object of the present invention is to provide a fuelequalization system which is capable of maintaining a desired air/fuelratio even during times of blocked air flow.

It is another object of the present invention is to provide a fuelequalization system which reduces the turbulence of a blocked air flow.

A further object of the invention is to position the air and fuel inletorifices some distance from the blower inlet, thereby isolating the airand fuel inlet orifices from excessive turbulence caused by anyblockages.

A further object of the invention is to decrease the number of clipsthat are engaged about the respective connected adjacent flange portionsto prevent leakage.

A further object of the invention is to provide a fuel equalizationsystem which substantially eliminates the creation of harmful gasbuild-up during times of partially or completely blocked air flows.

In accordance, therefore, with one embodiment, it is an object of thepresent invention to provide a fuel equalization system includes afilter box for accepting an air stream and a fuel stream, the air streamand the fuel stream mixing to form a mixed air/fuel stream. A blower isprovided that has an inlet for accepting the mixed air/fuel stream fromthe filter box. An air deflection member is positioned in the path ofthe mixed air/fuel stream, between the filter box and the inlet, so asto reduce the turbulence of the mixed air/fuel stream.

These and other objectives of the present invention, and their preferredembodiments, shall become clear by consideration of the specification,claims and drawings taken as a whole.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exploded view of a fuel equalization systemaccording to one embodiment of the present invention.

FIG. 2 is a partially exploded view of the fuel equalization system ofFIG. 1, in isolation.

FIG. 3 illustrates a schematic side view of a fuel equalization systemaccording to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates an exploded view of a fuel equalization system 10,according to one embodiment of the present invention. As shown in FIG.1, the fuel equalization system 10 includes a filter box 12 and a blower14. An air/fuel stream is directed by the blower 14 to a burner assembly16, which in turn is operatively connected to a boiler apparatus 18.

It will be readily appreciated that while the boiler apparatus 18 hasbeen described in connection with FIG. 1, the present invention is notso limited in this regard as the blower 14 may be connected to anysuitable apparatus without departing from the broader aspects of thepresent invention.

FIG. 2 illustrates the fuel equalization system in isolation. As shownin FIG. 2, the filter box 12 defines an inner box 20 having an airorifice and fuel entry 22. A duct section 24 is oriented between thefilter box 12 and the blower 14. An air stream and a fuel stream aredirected through the air orifice and fuel entry 22 via known means, andthis mixture is then sucked through the duct section 24 by the blower14, past an un-illustrated flue and into the burner assembly 16.

It is an important aspect of the present invention that the air orificeand fuel entry 22 is not positioned adjacent to the blower inlet 26, asis typically known in the art. Instead, the present invention arrangesthe air orifice and fuel entry 22 as far away as possible from theblower inlet 26, thereby isolating the air orifice and fuel entry 22,and any associated sensors, from the turbulence that may be caused byany air/fuel stream blockage.

Returning to FIG. 2, a static impeller 28 is arranged within the ductsection 24 and adjacent the blower inlet 26. As shown, the impeller 28enjoys a diameter that is slightly less then the diameter of theenclosing spool piece. When the outlet 30 of the blower 14 is partiallyor completely blocked, the resultant swirling air/fuel stream ‘backs up’and is redirected back through the duct section 24 and through theimpeller 28. The vanes 32 of the impeller 28 effectively reduce oreliminate the velocity and rotation of the redirected air/fuel streampassing there through.

The velocity and rotation of the re-directed air/fuel stream is furtherreduced or eliminated by the inclusion of a straightening blade 34, alsoformed in the duct section 24. As shown in FIG. 2, the straighteningblade 34 is a generally flat piece of metal or plastic, and ispreferably arranged along a diameter of the duct section 24. Thestraightening blade 34 acts as a baffle to intercept and furtherrestrain the swirling air/fuel stream, prior to the redirected air/fuelstream entering the filter box 12.

It is therefore another important aspect of the present invention thatthe static impeller 28 and the straightening blade 34 effectively reduceor eliminate any implied air flow into the filter box. That is, thestatic impeller 28 and the straightening blade 34 reduce the velocityand swirling nature of the air/fuel stream that is redirected backthrough the duct section 24. When coupled with positioning of the airorifice and fuel entry 22 a distance away from the blower inlet 26, thestatic impeller 28 and the straightening blade 34 effectively isolatethe air orifice and fuel entry 22 from the implied air flow that isgenerated by the blockage of the blower outlet 30. Thus, any sensorsmounted adjacent the air orifice and fuel entry 22 do not suffer fromimprecise readings, and the fuel equalization system 10 can therefore beoperated even in conditions of nearly complete blockage of the bloweroutlet 30, or the like.

While the straightening blade 34 in FIGS. 1 and 2 is shown as beingoriented substantially vertically, and extending substantially theentire diameter of the duct section 24, the present invention is notlimited in this regard. Indeed, the straightening blade 34 need notextend vertically, or across the entire diameter of the duct section 24,nor does the straightening blade 34 need to extend precisely along adiameter of the duct section 24, in order to substantially reduce oreliminate the velocity and swirling nature of the redirected, orimplied, air/fuel stream.

The embodiment shown and described in connection with FIGS. 1 and 2 hasdepicted a centrifugal blower 14, however the present invention is notlimited in this regard. FIG. 3 illustrates a schematic side view of afuel equalization system 50 according to another embodiment of thepresent invention. As shown in FIG. 3, the fuel equalization system 50includes a squirrel cage blower 52 operably connected to a filter box54. An air orifice and fuel entry 56 is formed in the filter box 54 andprovides the fuel equalization system 50 with the required air/fuelstream in a well known manner. Also shown in FIG. 3 is a squirrel cageimpeller 58 which is specially equipped with an air deflector plate 60.The deflector plate 60 is preferably arranged within the throat of theimpeller 58 and is shaped to capture the majority of the redirectedair/fuel flow, created by a blockage of the unillustrated blower outlet,or the like, back into the blower 52. In this manner, any swirling, highvelocity and redirected air/fuel stream created by a blockage of theblower outlet is largely kept within the blower 52, and consequentlydoes not adversely affect the air orifice and fuel entry 56, or anyrelated sensors disposed within the filter box 54.

The embodiment shown in FIG. 3 also arranges the air orifice and fuelentry 56 as far away from the blower inlet 62 as possible, similar tothe embodiment of FIGS. 1 and 2, so as to further isolate the airorifice and fuel entry 56 from the effects of any implied air flow.

A straightening blade, or baffle, 64 is located in the filter box 54 inmuch the same manner that the straightening blade 34 is arranged in theembodiments of FIGS. 1 and 2. That is, the straightening blade 64 islocated so as to substantially bisect the incoming redirected air/fuelstream, thereby reducing its velocity and swirling nature.

Although the embodiments of FIGS. 1-3 have illustrated the presentinvention as it is implemented in connection with a centrifugal blowersystem, and a squirrel cage blower system, the present invention is notso limited in this regard. Indeed, regardless of the type of blower thatis employed, or the nature of the apparatus to which the blower providesthe air/fuel mixture, the present invention envisions disposing astraightening blade/baffle within the path of any redirected air/fuelstream. The baffle itself may have a number of possible configurationsand dimensions, provided that it extends outwardly into the path of anyredirected air/fuel stream so as to reduce the velocity of theredirected air/fuel stream, as well as reducing the swirling nature ofthe redirected air/fuel stream.

The use of the static impeller 28, or the air deflector plate 60, incombination with locating the air orifice and fuel entry 56 as far aspossible from the blower inlet 26/62, also assists in reducing thevelocity of the redirected air/fuel stream, as well as reducing theswirling nature of the redirected air/fuel stream.

Thus, the present invention substantially eliminates the erroneoussensor readings and possible CO contamination stemming from a blockedblower outlet, or the like. By removing the effects of the implied airflow from the present fuel equalization system, the present invention iscapable of properly regulating the air/fuel mixture that is provided toa blower and burner assembly, up to and including properly regulatingthe air/fuel mixture even during times of near complete blockage of theblower outlet or burner flue.

While the invention has been described with reference to the preferredembodiments, it will be understood by those skilled in the art thatvarious obvious changes may be made, and equivalents may be substitutedfor elements thereof, without departing from the essential scope of thepresent invention. Therefore, it is intended that the invention not belimited to the particular embodiments disclosed, but that the inventionincludes all embodiments falling within the scope of the appendedclaims.

1. A fuel equalization system, comprising: a filter box for accepting anair stream and a fuel stream, said air stream and said fuel streammixing to form a mixed air/fuel stream; a blower having an inlet foraccepting said mixed air/fuel stream from said filter box; and a baffledisposed in the path of said mixed air/fuel stream, wherein said baffleis located between said filter box and said inlet.
 2. The fuelequalization system of claim 1, wherein: said mixed air/fuel stream isconveyed from said filter box to said inlet via a duct; and said bafflesubstantially bisects said duct.
 3. The fuel equalization system ofclaim 2, further comprising: a static impeller positioned within saidduct, and adjacent said inlet.
 4. The fuel equalization system of claim1, wherein: said blower is a squirrel cage blower having an integratedsquirrel cage impeller; and an air deflector plate is arranged to extendinto a throat of said squirrel cage impeller.
 5. A fuel equalizationsystem, comprising: a filter box for accepting an air stream and a fuelstream, said air stream and said fuel stream mixing to form a mixedair/fuel stream; a blower having an inlet for accepting said mixedair/fuel stream from said filter box; and an air deflection meanspositioned in a path of said mixed air/fuel stream, between said filterbox and said inlet so as to reduce any turbulence in said mixed air/fuelstream.
 6. The fuel equalization system of claim 5, wherein: said mixedair/fuel stream is conveyed from said filter box to said inlet via aduct; and said air deflection means is a baffle that substantiallybisects said duct.
 7. The fuel equalization system of claim 5, wherein:said mixed air/fuel stream is conveyed from said filter box to saidinlet via a duct; and said air deflection means is a static impellerpositioned within said duct, and adjacent said inlet.
 8. The fuelequalization system of claim 6, further comprising: a static impellerpositioned within said duct, and adjacent said inlet.
 9. The fuelequalization system of claim 7, further comprising: a baffle thatsubstantially bisects said duct.
 10. The fuel equalization system ofclaim 5, wherein: said blower is a squirrel cage blower having anintegrated squirrel cage impeller; and an air deflector plate isarranged to extend into a throat of said squirrel cage impeller.
 11. Amethod of reducing turbulence within a mixed air/fuel stream beingprovided to a blower, said method comprising the steps of: arranging afilter box to be in fluid communication with said blower; providing saidfilter box with said mixed air/fuel stream; channeling said mixedair/fuel stream along a path from said filter box to said blower;arranging an inlet opening in said blower to accept said mixed air/fuelstream; and positioning an air deflection means in said path so as toretard the velocity and swirling nature of said mixed air/fuel stream.12. A method of reducing turbulence within a mixed air/fuel stream beingprovided to a blower according to claim 11, said method furthercomprising the steps of: forming a duct between said filter box and saidinlet so as to define said path; and forming said air deflection meansas a baffle that substantially bisects said duct.
 13. A method ofreducing turbulence within a mixed air/fuel stream being provided to ablower according to claim 11, said method further comprising the stepsof: forming a duct between said filter box and said inlet so as todefine said path; and forming said air deflection means as a staticimpeller positioned within said duct, and adjacent said inlet.
 14. Amethod of reducing turbulence within a mixed air/fuel stream beingprovided to a blower according to claim 12, said method furthercomprising the steps of: positioning a static impeller within said duct,and adjacent said inlet.
 15. A method of reducing turbulence within amixed air/fuel stream being provided to a blower according to claim 13,said method further comprising the steps of: positioning a baffle withinsaid duct, said baffle substantially bisecting said duct.
 16. A methodof reducing turbulence within a mixed air/fuel stream being provided toa blower according to claim 11, said method further comprising the stepsof: forming said blower as a squirrel cage blower having an integratedsquirrel cage impeller; and arranging an air deflector plate so as toextend into a throat of said squirrel cage impeller.